Phylogenomics and morphological evolution of the mega-diverse genus Artemisia (Asteraceae: Anthemideae): implications for its circumscription and infrageneric taxonomy.

BACKGROUND AND AIMS: Artemisia is a mega-diverse genus consisting of ~400 species. Despite its medicinal importance and ecological significance, a well-resolved phylogeny for global Artemisia, a natural generic delimitation and infrageneric taxonomy remain missing, owing to the obstructions from limited taxon sampling and insufficient information on DNA markers. Its morphological characters, such as capitulum, life form and leaf, show marked variations and are widely used in its infrageneric taxonomy. However, their evolution within Artemisia is poorly understood. Here, we aimed to reconstruct a well-resolved phylogeny for global Artemisia via a phylogenomic approach, to infer the evolutionary patterns of its key morphological characters and to update its circumscription and infrageneric taxonomy. METHODS: We sampled 228 species (258 samples) of Artemisia and its allies from both fresh and herbarium collections, covering all the subgenera and its main geographical areas, and conducted a phylogenomic analysis based on nuclear single nucleotide polymorphisms (SNPs) obtained from genome skimming data. Based on the phylogenetic framework, we inferred the possible evolutionary patterns of six key morphological characters widely used in its previous taxonomy. KEY RESULTS: The genus Kaschgaria was revealed to be nested in Artemisia with strong support. A well-resolved phylogeny of Artemisia consisting of eight highly supported clades was recovered, two of which were identified for the first time. Most of the previously recognized subgenera were not supported as monophyletic. Evolutionary inferences based on the six morphological characters showed that different states of these characters originated independently more than once. CONCLUSIONS: The circumscription of Artemisia is enlarged to include the genus Kaschgaria. The morphological characters traditionally used for the infrageneric taxonomy of Artemisia do not match the new phylogenetic tree. They experienced a more complex evolutionary history than previously thought. We propose a revised infrageneric taxonomy of the newly circumscribed Artemisia, with eight recognized subgenera to accommodate the new results.

A set of novel microsatellite markers developed for the traditional Tibetan medicinal plant Halenia elliptica (Gentianaceae).

PREMISE OF THE STUDY: Microsatellite primers were developed in the traditional Tibetan medicinal plant Halenia elliptica D. Don to investigate its genetic diversity and population genetic structure. METHODS AND RESULTS: Using the Fast Isolation by AFLP of Sequences Containing (FIASCO) repeats protocol, 24 primer sets were identified in two wild populations. Of these primers, 12 displayed polymorphisms and 12 were monomorphic. The number of alleles per locus ranged from 2 to 6, with a mean of 3.9. The expected (H(E)) and observed (H(O)) heterozygosities ranged from 0.191 to 0.784 and from 0.417 to 0.917, respectively. All these primers successfully amplified in two close relatives of H. elliptica, Swertia bimaculata (Siebold & Zucc.) Hook. f. & Thomson ex C. B. Clarke and S. tetraptera Maxim. CONCLUSIONS: These markers will facilitate further studies on the population genetics of Halenia elliptica and its allied species.

Ancient Chinese literature reveals pathways of eggplant domestication.

BACKGROUND AND AIMS: Changes in key traits occurring during the processes of plant domestication have long been subjects of debate. Only in the case of genetic analysis or with extensive plant remains can specific sets of changes be documented. Historical details of the plant domestication processes are rare and other evidence of morphological change can be difficult to obtain, especially for those vegetables that lack a substantial body of archaeological data. Botanical records chronicled in the ancient literature of established ancient civilizations, such as that of China, are invaluable resources for the study and understanding of the process of plant domestication. Here, the considerable body of ancient Chinese literature is used to explore the domestication process that has occurred with the eggplant (Solanum melongena), an important vegetable in Old World. METHODS: Information about eggplant domestication in the ancient Chinese literature was retrieved using a variety of methods. The information obtained was then sorted by taxon, examined and taxonomic identifications verified. KEY RESULTS: It was found that the earliest record of the eggplant documented in ancient Chinese literature was in a work from 59 bc. As far as is known, this is the earliest reliable and accurately dated record of eggplant in cultivation. The analysis reveals that the process of domestication of the eggplant in China involved three principal aspects of fruit quality: size, shape and taste. These traits were actively and gradually selected; fruit size changed from small to large, taste changed from not palatable to what was termed at the time sweetish, and that over time, a wider variety of fruit shapes was cultivated. CONCLUSIONS: The results indicate that, in addition to data gleaned from archaeology and genetics, evidence as to changes in key traits occurring during the process of plant domestication and selective forces responsible for these changes can be traced through the ancient literature in some civilizations.